Pole-shoe for dynamo-electric machines.



PATENTED 2 313.25, 1908.

'R. B. TREAT. POLE SHOP; FOR- DYNIAMO ELECTRIC MACHINES.

APPLIGATION FILED APE. 9.1906.

Fig. 2-

Inventor, fiabim B. Treat,

Allah WHIIBSSBS ':TREAT, a citizen of the United States of electric machines, and the novel features re- 16" construction for the tips of pole shoes whereby a'crowdin of the lines of magnetic force ROBERTBELDEN TREAT, or NEWARKNEW- COMPANY, OF AMPEIRE, NE-W'JERSEY,

Todll 1bh0m it may concem:

Be it knownthat 1, ROBERT BELDEN America, and a resident of Newark, county of Essex, and State ofNew Jersey, have invented certain new and useful Improvements in Pole-Shoes for Dynamo-Electric Machines, of which the following is a specification.

My invention relates to the construction of pole shoes for the fieldmagnets of dynamo side especially in the construction of the tips .of the pole shoes which overhang the cores to which the shoes are attached.

The object of theinvention is to provide a therein and distortion of the magnetic field through armature reactions is prevented,

and to attain this in a construction Vt ith an unbroken polar sprface and a rigidconstruc- .tion of the tips.

A further object of the invention is to provide a' construction whereby the magneticfiu'x is progressively diminished toward the point of the tip so that the magnetic attraction'between each armature tooth and the ole shoe is progressively reduced as the toot approaches the extreme tip of the pole and less jar and. vibration is occasioned by the breaking away of the armature, teeth from their magnetic attraction to the pole shoe. l

- f Inthe accompanying sheet of drawings which forms a part of this application,

- Figure 1 is an elevation of the frame of a dynamo electric machine with field coils in section and provided itll pole shoes vembodying my invention, the armature being, contained within the'frame and the supports for the armatureshaft being omitted. Fig.

2 is a face view of one of the pole-shoes.

The invention isillustrated in connection with a four-pole dynamo electric machine inwhich a frame A- supports four inwardly projecting poles or cores B B wh ich carry magnet windings C C for the excitation of magnetism in the cores. Pole shoes D D, formed of sheet iron, held together by rivets t t, are fastened to the ends o f the cores by screws s s. The faces of the poleshoes are larger than the faces of the cores and-are Specification of Letters Patent. Application filed April 9. 1906- Scrial No. 310.588.

.the tip.

. t i JERSEY, ASSIGNOR TO CROGKER-WHEELER A CORPORATION OF NEW JERSEY.

POLE-SHOE FOR 'DYNAMO-ELECTRIC MACHINES..

. separablejfrom the cores to permit of laminated construction and also so that formed Patented Feb. 25, 1908.

field coils may he slipped onto the cores when the pole shoes are removed. The portions of the pole shoes which overhang the cores are the pole tips (1 (Z. The end portions of each of the laminations of the pole shoes, which together form these pole ti s,

are perforated at p p, and in the assemb ed laminations these perforations form tunnels parallelto the axis of the machine and through the pole tips wholly below the polar surface of the pole shoe and serve to cut down the area of metal which connects the tips with the bodies of the poleshoe, whereby the magnetization through'this' connect ing metal is at all times practically saturated and therefore cannot be further increased by cross-magnetization from armature reactions and the magnetic field distorted.

The erforations in the lamina of each of the o e shoes are preferably elongated in,

the irection of the tips, the axis of the elon- '7 5 gation being inclined to the face of the pole shoe at the tip, so that the extreme end of the ti) is supported fromthe body of the pole shoe by twobranches of metal with the branch ewhich-lies onthe face side of tri- 30 angular form, the base of the triangle being toward the body of the pole shoe. This branch is chiefly instrumental in conducting the magnetization into the tipfrom the body "of the shoe, and by reason of its progressively diminishing cross section toward the point of. the tip a similar graduation in the magnetic flux is insured. The other branch f lies on the rear side and serves as a brace to What I claim as new and desire to secure bylietters'Patentof the United States is:

A pole shoe for a dynamo electric machine provided with pole" tips, each having an elongated perforation inclined to the face of the pgleshoe'at the tip, substantially as described. Signed by me at Ampere, N. J., this 3d day of April, 1906.

ROBERT BELDEN Witnesses:

FREDERICK E. WARD,- EDWIN R. DOUGLAS.

TREAT. 

